Unlike the cathode-ray tubes (CRTs) used as the display devices of most computers and televisions, a flat-panel display is flat, light, thin, and uses little power. They are rapidly replacing CRTs [49]. A liquid-crystal display (LCD) is one particular kind of flat-panel display; it is a sandwich of glass containing crystals of amorphous silicon or other materials that change the way they polarize light in response to electricity. Electrodes on the back of the screen can be used to display information by polarizing light in different parts of the display.
In 1990 Japan's Ministry of International Trade and Industry sponsored a $100-million project to develop a 40-inch flat-panel display by 1996 [1]. In 1990 and 1991 alone, Sharp, Sanyo, Matsushita, Hitachi, Hoshiden, Toshiba-IBM, Mitsubishi, and NEC together committed almost $2.25 billion to develop active-matrix liquid-crystal displays [12]. Worldwide annual sales of flat screens now exceed $2 billion [19].